The invention relates to the field of optical communication, and in particular to magnetooptical isolators having high faraday rotation that can be integrated on InP and GaAs substrates.
Optical isolators are widely used to isolate active optoelectronic components, such as lasers and optical amplifiers, from unwanted optical feedback. The isolators available today utilize bulk magneto-optical materials (crystals of yttrium iron garnet or bismuth iron garnet) and birefringent crystals (lithium niobate) or bulk optical polarizers. These bulk optical components made from non-semiconducting materials cannot be easily integrated with semiconductor lasers and optical amplifiers. There is a need in the art to have magnetically active semiconductor waveguide structures so as to enable the monolithic integration of optical isolators and circulators with semiconductor optoelectronic devices.